The present invention relates to a graph drawing apparatus and, more particularly, to an electronic graph drawing apparatus or graph plotter capable of printing out graphs according to input numerical data.
Conventionally, graph drawing apparatuses apply the maximum of input numerical data directly to the maximum point of the graph scale and, in addition, the distance between the minimum of the scale and the maximum of the scale is divided into equal sections for proper scaling.
Therefore, when the maximum of the input numerical data is not a whole number, having a fractional portion designated by numerals to the right of a decimal point, all of the scale items between the maximum scale and the respective scale sections are formed by calculations including this decimal fraction. This is disadvantageous in that the resultant graph becomes unnatural and difficult to read.
Further, in the conventional graph drawing apparatuses, the respective sectional scale items are printed out only on the X- and the Y-axis, so that any graph paper can be used to draw a line graph and a bar graph, but it is difficult to use roll paper having no sectional scale items far from the X- and the Y-axis because the relation between the scale items and the numerical data is uncertain to the person studying the graph.